Fix collapseAttributeWhitespace issue

.github/workflows/npm.yml

@@ -28,6 +28,4 @@ jobs:
       - name: "Run tests"
         run: npm test
       - name: "Publish"
-        run: npm publish --provenance
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+        run: npm publish

CHANGELOG.md

@@ -4,7 +4,11 @@ As of version 5.0.0, all notable changes to HTML Minifier (HM) are documented in
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and the project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [5.2.0] - 2026-11-14
+
+### Fixed
+
+* Fixed `collapseAttributeWhitespace` adding spaces around custom fragments in attribute values (e.g., `href="/invoices/<?= $inv->id ?>?tab=lines"` became `href="/invoices/ <?= $inv->id ?> ?tab=lines"`)
 
 ### Added
 

package.json

@@ -17,11 +17,11 @@
     "@eslint/js": "^10.0.1",
     "@swc/core": "^1.16.22",
     "@types/node": "^26.6.6",
-    "eslint": "^10.14.0",
+    "eslint": "^10.15.0",
     "globals": "^17.14.0",
     "parse5": "^8.1.1",
     "typescript": "^7.0.2",
-    "vite": "^8.3.7"
+    "vite": "^8.3.8"
   },
   "engines": {
     "node": ">=22.13"
@@ -95,5 +95,5 @@
   },
   "type": "module",
   "types": "dist/types/htmlminifier.d.ts",
-  "version": "5.1.0"
+  "version": "5.2.0"
 }

src/lib/attributes.js

@@ -11,6 +11,7 @@ import {
   RE_BASE_ELEMENT,
   RE_ATTR_WS_CHECK,
   RE_ATTR_WS_COLLAPSE,
+  RE_TABS_ONLY,
   RE_WS_CHAR,
   generalDefaults,
   tagDefaults,
@@ -751,11 +752,28 @@ const valueWhitespaceExemptElements = new Set(['button', 'data', 'input', 'optio
 
 /**
  * @param {string} value
+ * @param {string[]} [markers] - What custom fragment and `htmlmin:ignore` placeholders hold
  * @returns {string}
  */
-function collapseAttributeValue(value) {
+function collapseAttributeValue(value, markers = []) {
   // Fast path: Only process if whitespace exists (avoids regex overhead on clean values)
-  return RE_ATTR_WS_CHECK.test(value) ? trimWhitespace(value).replace(RE_ATTR_WS_COLLAPSE, ' ') : value;
+  if (!RE_ATTR_WS_CHECK.test(value)) {
+    return value;
+  }
+  value = trimWhitespace(value);
+  if (!markers.some(marker => value.indexOf(marker) !== -1)) {
+    return value.replace(RE_ATTR_WS_COLLAPSE, ' ');
+  }
+  // Placeholders come padded with a tab on each side, which restoring them drops; as spaces,
+  // they would stay, while other tabs (e.g., decoded ones) must become a space that stays
+  return value.replace(RE_ATTR_WS_COLLAPSE, (run, offset) => {
+    if (!RE_TABS_ONLY.test(run)) {
+      return ' ';
+    }
+    const paddingBefore = markers.some(marker => value.endsWith(marker, offset)) ? '\t' : '';
+    const paddingAfter = markers.some(marker => value.startsWith(marker, offset + run.length)) ? '\t' : '';
+    return run.length > paddingBefore.length + paddingAfter.length ? paddingBefore + ' ' + paddingAfter : run;
+  });
 }
 
 /**
@@ -791,7 +809,7 @@ function cleanAttributeValue(tag, attrName, attrValue, options, attrs, minifyHTM
   // with `collapseWhitespace`; an `annotation-xml` encoding is matched as written,
   // and with spaces taken out could make the element hold HTML
   if (options.collapseAttributeWhitespace && !collapseAttributeWhitespaceExempt.has(attrName) && !(attrName === 'value' && valueWhitespaceExemptElements.has(tag)) && !(attrName.toLowerCase() === 'encoding' && tag.toLowerCase() === 'annotation-xml') && !isEventAttr) {
-    attrValue = collapseAttributeValue(attrValue);
+    attrValue = collapseAttributeValue(attrValue, markers);
   }
 
   if (isEventAttr) {

src/lib/constants.js

@@ -52,6 +52,7 @@ const RE_DOCTYPE = /^<!doctype[ \n\r\t\f]*([^ \n\r\t\f>]+)[ \n\r\t\f]*(?:public[
 const RE_DOCTYPE_SEGMENT = /("[^"]*(?:"|$)|'[^']*(?:'|$))|[^"']+/g;
 const RE_ATTR_WS_CHECK = /[ \n\r\t\f]/;
 const RE_ATTR_WS_COLLAPSE = /[ \n\r\t\f]+/g;
+const RE_TABS_ONLY = /^\t+$/;
 const RE_WS_CHAR = /\s/;
 const RE_STYLE_ELEMENT = /<style[\s/>]/i;
 const RE_STYLE_TAG = /<\/?style/gi;
@@ -460,6 +461,7 @@ export {
   RE_DOCTYPE_SEGMENT,
   RE_ATTR_WS_CHECK,
   RE_ATTR_WS_COLLAPSE,
+  RE_TABS_ONLY,
   RE_WS_CHAR,
   RE_STYLE_ELEMENT,
   RE_STYLE_TAG,

test/html.test.js

@@ -7090,6 +7090,43 @@ describe('HTML', () => {
     assert.strictEqual(await minify(input, { collapseAttributeWhitespace: true, minifyJS: true }), '<button onclick=\'alert("→     ←")\'>x</button>');
   });
 
+  test('Collapses attribute whitespace without adding any around custom fragments', async () => {
+    const options = { collapseAttributeWhitespace: true };
+    for (const input of [
+      '<a href="/invoices/<?= $inv->id ?>?tab=lines">x</a>',
+      '<a data-path="/i/<?= $id ?>?t=1">x</a>',
+      '<a data-x="a<?= $a ?><?= $b ?>b">x</a>',
+      '<a data-x="a<% x %>b">x</a>',
+      '<a style="color:<?= $c ?>">x</a>'
+    ]) {
+      assert.strictEqual(await minify(input, options), input);
+      assert.strictEqual(await minify(input, { ...options, collapseWhitespace: true }), input);
+      assert.strictEqual(await minify(input, { ...options, collapseWhitespace: true, trimCustomFragments: true }), input);
+    }
+
+    // Whitespace written next to a fragment stays (collapsed with `collapseWhitespace`)
+    let input = '<a data-x="a  <?= $a ?>\n\tb">x</a>';
+    assert.strictEqual(await minify(input, options), input);
+    assert.strictEqual(await minify(input, { ...options, collapseWhitespace: true }), '<a data-x="a <?= $a ?> b">x</a>');
+
+    // Decoded whitespace next to a fragment stays, as one space
+    for (const [source, expected] of [
+      ['<a data-x="a&#9;<?= $a ?>b">x</a>', '<a data-x="a <?= $a ?>b">x</a>'],
+      ['<a data-x="a<?= $a ?>&#9;&#9;b">x</a>', '<a data-x="a<?= $a ?> b">x</a>'],
+      ['<a data-x="a<?= $a ?>&#9;<?= $b ?>b">x</a>', '<a data-x="a<?= $a ?> <?= $b ?>b">x</a>']
+    ]) {
+      assert.strictEqual(await minify(source, { ...options, decodeEntities: true }), expected);
+      assert.strictEqual(await minify(source, { ...options, decodeEntities: true, collapseWhitespace: true }), expected);
+    }
+
+    // Elsewhere, whitespace still collapses
+    input = '<a data-x="  a\t\tb <?= $a ?>c   d  ">x</a>';
+    assert.strictEqual(await minify(input, options), '<a data-x="a b <?= $a ?>c d">x</a>');
+
+    // The comprehensive preset, as reported
+    assert.strictEqual(await minify('<a href="/invoices/<?= $inv->id ?>?tab=lines">x</a>', { preset: 'comprehensive' }), '<a href="/invoices/<?= $inv->id ?>?tab=lines">x</a>');
+  });
+
   test('Decodes entity characters', async () => {
     let input, output;